U.S. patent application number 13/580538 was filed with the patent office on 2013-01-31 for disposable wearing article.
This patent application is currently assigned to UNICHARM CORPORATION. The applicant listed for this patent is Takaya Arayama, Hirotomo Mukai. Invention is credited to Takaya Arayama, Hirotomo Mukai.
Application Number | 20130030398 13/580538 |
Document ID | / |
Family ID | 44506533 |
Filed Date | 2013-01-31 |
United States Patent
Application |
20130030398 |
Kind Code |
A1 |
Arayama; Takaya ; et
al. |
January 31, 2013 |
DISPOSABLE WEARING ARTICLE
Abstract
A disposable diaper has a central slit formed along the
lengthwise direction L so that the absorber can be curved to be
convex in the inward direction, and a pair of side slits formed
along the lengthwise direction L so that the absorber can be curved
to be convex in the outward direction. An average total weight of a
water absorbent polymer at the central portion CT and the side edge
portion S.sub.L, S.sub.R is smaller than an average total weight of
the water absorbent polymer at the middle portion M.sub.L,
M.sub.R.
Inventors: |
Arayama; Takaya; (Kagawa,
JP) ; Mukai; Hirotomo; (Kagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Arayama; Takaya
Mukai; Hirotomo |
Kagawa
Kagawa |
|
JP
JP |
|
|
Assignee: |
UNICHARM CORPORATION
Ehime
JP
|
Family ID: |
44506533 |
Appl. No.: |
13/580538 |
Filed: |
February 25, 2011 |
PCT Filed: |
February 25, 2011 |
PCT NO: |
PCT/JP2011/001122 |
371 Date: |
October 12, 2012 |
Current U.S.
Class: |
604/367 |
Current CPC
Class: |
A61F 13/535 20130101;
A61F 13/49001 20130101; A61F 2013/5307 20130101; A61F 2013/53051
20130101 |
Class at
Publication: |
604/367 |
International
Class: |
A61F 13/53 20060101
A61F013/53 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 27, 2010 |
JP |
2010-043596 |
Claims
1. A disposable wearing article, comprising: an absorber having a
lengthwise direction; a widthwise direction which is orthogonal to
the lengthwise direction; an inward direction which is oriented to
a wearer; and an outer direction which is oriented to a side
opposite to the inward direction, the absorber including a water
absorbent polymer, wherein: the absorber has, in a crotch portion
region applied to a crotch portion of the wearer, a central portion
which is formed at a central part of the absorber in the widthwise
direction, a pair of side edge portions including a side edge of
the absorber in the widthwise direction, and a pair of middle
portions which are positioned between the central portion and the
side edge portions; at the central portion, a central curve forming
portion is formed along the lengthwise direction so that the
absorber can be curved to be convex in the inward direction; at
each of the middle portions, a side curve forming portion is formed
along the lengthwise direction so that the absorber can be curved
to be convex in the outward direction; and an average total weight
of the water absorbent polymer at the central portion and the side
portion is smaller than an average total weight of the water
absorbent polymer at the middle portions.
2. The disposable wearing article according to claim 1, wherein:
the middle portions each include an inside middle portion which is
a region from the side curve forming portion to a boundary
associated with the central portion in the widthwise direction; the
central portion includes a sub-central portion from a boundary
associated with a respective one of the middle portions to the
central curve forming portion in the widthwise direction; and an
average total weight of the water absorbent polymer at the
sub-central portion is less than an average total weight of the
water absorbent polymer at the inside middle portion.
3. The disposable wearing article according to claim 1, wherein:
the middle portions each include an outside middle portion which is
a region from the side curve forming portion to a boundary
associated with a respective one of the side edge portions in the
widthwise direction; and an average total weight of the water
absorbent polymer at the side edge portion is smaller than an
average total weight of the water absorbent polymer at the outside
middle portion.
4. The disposable wearing article according to claim 1, wherein one
or both of the middle portions is formed, in the widthwise
direction, from a position which corresponds to half of a distance
between a center of the central curve forming portion and a center
of the side curve forming portions, to a position which corresponds
to half of a distance between the center of the side curve forming
portion and a side edge of the absorber.
5. The disposable wearing article according to claim 2, wherein, in
the widthwise direction, a width of the central portion is
identical to a width of one or both of the side edge portions.
6. The disposable wearing article according to claim 1, wherein, in
the lengthwise direction, an average total weight of the water
absorbent polymer in a region positioned outside of the central
portion is larger than an average total weight of the water
absorbent polymer at the central portion.
7. The disposable wearing article according to claim 1, wherein a
thickness of the absorber in any of at least the central portion
and the side end portion is smaller than a thickness of the
absorber at the middle portion.
8. The disposable wearing article according to claim 1, wherein:
the absorber has a first layer and a second layer which are
superimposed on one another; the central portion and the side edge
portion are formed of only the second layer; and the middle portion
is formed of the first layer and the second layer.
9. The disposable wearing article according to claim 8, wherein the
average total weight of the water absorbent polymer in the first
layer is smaller than the average total weight of the water
absorbent polymer in the second layer.
10. The disposable wearing article according to claim 9, wherein:
the second layer is positioned at a skin contact surface side with
the wearer; and the first layer is positioned at a non-skin contact
surface side of the wearer.
11. The disposable wearing article according to claim 1, wherein
the central curve forming portion is formed of a central slit which
is formed at the absorber along the lengthwise direction, or is
formed of a central elastic member which is disposed along the
lengthwise direction.
12. The absorber according to claim 1, wherein the side curve
forming portion is formed of a side slit which is formed at the
absorber along the lengthwise direction.
13. A disposable wearing article, comprising an absorber having a
lengthwise direction, a widthwise direction which is orthogonal to
the lengthwise direction, an inward direction which is oriented to
a wearer, and an outward direction which is oriented to an opposite
side to the inward direction, the absorber including a water
absorbent polymer, wherein: the absorber includes, in a crotch
portion region applied to a crotch portion of the wearer, a central
portion which is formed at a central part of the absorber in the
widthwise direction; a pair of side edge portions which are formed
at side edge of the absorber in the widthwise direction; and a pair
of middle portions which are positioned between the central portion
and the side edge portions; at the central portion, a central curve
forming portion is formed along the lengthwise direction so that
the absorber can be curved to be convex in the inward direction; at
the middle potions, a pair of side curve forming portions are
formed along the lengthwise direction so that the absorber can be
curved to be convex in the outward direction; the middle portion
includes, in the widthwise direction, an inside middle portion
which is a region from the side curve forming portion to a boundary
associated with the central portion; and an outside middle portion
which is a region from the side curve forming portion to a boundary
of the side edge portion; the central portion includes, in the
widthwise direction, a sub-central portion which is a region from a
boundary associated with the middle portion to the central curve
forming portion; and in a case where the absorber absorbs a
predetermined amount of liquid, a total thickness of the absorber
at the sub-central portion and the side edge portion is adapted to
be smaller than a total thickness of the absorber at the inside
middle portion and the outside middle portion.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a disposable wearing
article which is provided with an absorber including a water
absorbent polymer, wherein a curve forming portion for curving the
absorber is formed at the absorber.
BACKGROUND ART
[0002] In disposable wearing articles such as pant-type diapers, a
variety of contrivances are made in order to improve the feeling of
a wearer or prevent leakage of bodily waste. For example, there is
known a pant-type diaper in which three curve forming portions are
formed along a lengthwise direction of an absorber at the absorber
for absorbing bodily waste of a wearer (Japanese Patent Application
Publication No. 2006-346439, for example).
[0003] Specifically, in this pant-type diaper, three slits are
formed at the absorber, and peripheral portions of the slits each
are curved. The central slit peripheral portion is formed to be
convex toward an excretion portion of the wearer. In addition, a
lateral slit peripheral portion is formed to be convex at an
opposite side of the central slit peripheral portion. Namely, a
cross-cross-sectional shape of the absorber along a widthwise
direction of the absorber is deformed in a W-letter shape.
[0004] Thus, the convex portion of the absorber, which is formed by
the central slit peripheral portion, easily comes into intimate
contact with a wearer's excretion portion. In addition, bodily
waste easily enters a concave portion which is formed by two
outside slit peripheral portions to be thereby able to restrain
bodily waste from coming into direct contact with the wearer's
skin.
SUMMARY OF INVENTION
[0005] However, if the amount of the water absorbent polymer that
is included in the absorber is increased in an attempt to improve
absorptive power of the conventional pant-type diaper described
above, the following problem occurs. That is, if an absorber of
which total weight of the water absorbent polymer is large absorbs
bodily waste, the absorber swells greatly and then becomes thick,
and a wearer easily has an uncomfortable feeling if his or her legs
are closed, for example, at the time of taking a standing
position.
[0006] In addition, the absorber is positioned in a state in which
it is curved at a wearer's crotch portion, and thus, if the
absorber swells, it cannot be sufficiently curved, and the absorber
hardly comes into contact with the wearer's excretion portion.
Thus, there has still remained unsolved the problem that urine or
watery stool or the like easily leaks to the outside with it going
along the wearer's skin.
[0007] Therefore, it is an object of the present invention to
provide a disposable wearing article, such as a pant-type diaper,
which is capable of more reliably restraining an uncomfortable
feeling of a wearer even after absorption of bodily waste or
leakage of bodily waste while further improving absorptive
power.
[0008] A disposable wearing article according to the present
invention in a first aspect includes an absorber having: a
lengthwise direction; a widthwise direction which is orthogonal to
the lengthwise direction; an inward direction which is oriented to
a wearer; and an outer direction which is oriented to a side
opposite to the inward direction, the absorber including a water
absorbent polymer. The absorber has, in a crotch portion region
applied to a crotch portion of the wearer, a central portion which
is formed at a central part of the absorber in the widthwise
direction, a pair of side edge portions including a side edge of
the absorber in the widthwise direction, and a pair of middle
portions which are positioned between the central portion and the
side edge portion; at the central portion, a central curve forming
portion is formed along the lengthwise direction so that the
absorber can be curved to be convex in the inward direction; at the
middle portion, a pair of side curve forming portions are formed
along the lengthwise direction so that the absorber can be curved
to be convex in the outward direction; and an average total weight
of a water absorbent polymer at the central portion and the side
edge portion is smaller than an average total weight of the water
absorbent polymer at the middle portion.
[0009] According to the characteristics of the present invention,
there can be provided a disposable wearing article, such as a
pant-type diaper, featuring the absorber, which is capable of more
reliably restraining an uncomfortable feeling of a wearer even
after absorption of bodily waste or leakage of bodily waste while
further improving absorptive power.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 is a schematic perspective view of a diaper 1
according to a first embodiment.
[0011] FIG. 2 is an exploded plan view of the diaper 1 according to
the first embodiment.
[0012] FIG. 3 is a widthwise sectional view of the diaper 1 taken
along the line A-A shown in FIG. 2.
[0013] FIG. 4 is a lengthwise sectional view of the diaper 1 taken
along the line B-B shown in FIG. 2.
[0014] FIG. 5 is a plan view of an absorber 40 according to the
first embodiment.
[0015] FIG. 6 is a partially enlarged plan view of the absorber 40
according to the first embodiment.
[0016] FIG. 7(a) is a sectional view schematically showing a
wearing state of a disposable diaper 1 while the absorber 40
according to the first embodiment does not absorb bodily waste; and
FIG. 7(b) is a sectional view schematically showing a wearing state
of the disposable diaper 1 while the absorber 40 absorbs bodily
waste.
[0017] FIG. 8 is a sectional view (at the time of closing legs)
schematically showing a wearing state of the disposable diaper 1 in
which the absorber 40 according to the first embodiment absorbs
bodily waste.
[0018] FIG. 9 is a partially enlarged plan view of the disposable
diaper 1 according to a modification of the first embodiment.
[0019] FIG. 10 is a sectional view of the disposable diaper 1
according to a modification of the first embodiment.
[0020] FIG. 11 is a sectional view of the disposable diaper 1
according to a modification of the first embodiment.
[0021] FIG. 12 is a perspective view of a simple absorber 40Z
according to a second embodiment.
[0022] FIG. 13 is a sectional view of a disposable diaper 1
according to the second embodiment.
DESCRIPTION OF EMBODIMENT
[0023] Next, the embodiments of a disposable wearing article
comprising the absorber, according to the present invention, will
be described with reference to the drawings. In the description of
drawings that follow, the same or like constituent elements are
designated by the same or like reference numerals. However, it
should be kept in mind that the drawings are schematic and ratios
or the like of dimensions each may be different from an actual
one.
[0024] Therefore, specific dimensions or the like should be
determined in consideration of the following description. In
addition, portions with different dimensional interrelationships or
ratios can be included in the drawings as well.
First Embodiment
[0025] A disposable wearing article according to the embodiment is
provided with a central curve forming portion and a pair of side
curve forming portions, and is characterized in that an average
total weight of a water absorbent polymer at a central portion,
which is a region including a position of the central curve forming
portion, and at a side edge portion, which is a region including a
side edge of the absorber, is less than the average total weight of
the water absorbent polymer at a middle portion, which includes the
side curve forming portions.
[0026] (1) Entire Schematic Configuration of Disposable Wearing
Article
[0027] FIG. 1 is a schematic perspective view of a disposable
diaper 1, which comprises a. As shown in FIG. 1, the disposable
diaper 1 is a pant-type disposable diaper. The disposable diaper 1
is provided with: an exterior topsheet 70, a foreside exterior
backsheet 80F and a backside exterior backsheet 80R, which
configure an exterior portion of the disposable diaper 1. An
absorber 40 comprised of a cotton-like pulp and a highly
polymerized water absorbent polymer (hereinafter, referred to as a
water absorbent polymer) is provided inside (on a skin contact
surface side) of the external top sheet 70.
[0028] A plurality of curve forming portions are formed in the
absorber 40. In the depicted arrangement these curve forming
portions comprise slits, however, the curve forming portions may
take other forms, as will be readily appreciated by those skilled
in the art. A central slit 45 is formed at a center in a widthwise
direction of the absorber 40. In addition, a side slit 46L and a
side slit 46R are formed one either side of the central slit 45. By
means of these slits that are formed at the absorber 40, the
absorber 40 is configured so that it can be curved when the
disposable diaper 1 is worn.
[0029] FIG. 2 is an exploded plan view of the disposable diaper 1
according to the embodiment. FIG. 3 is a widthwise sectional view
of the disposable diaper 1 taken along the line A-A shown in FIG.
2. FIG. 4 is a lengthwise sectional view of the disposable diaper 1
taken along the line B-B shown in FIG. 2.
[0030] As shown in FIG. 2 to FIG. 4, the disposable diaper 1 has: a
front waistline region S2 which corresponds to a wearer's front
waistline; and a back waistline region S3 which corresponds to the
wearer's back waistline. The disposable diaper 1 also has a crotch
portion region S1, a foreside middle inside leg region S4 and a
backside middle inside leg region S5.
[0031] The crotch portion region S1 is a region applied to a
wearer's crotch portion at which a width between both legs is the
narrowest when the wearer closes his or her legs. The foreside
middle inside leg region S4 is positioned between the crotch
portion region Si and the front waistline region S2 in a lengthwise
direction L of an absorber 40. The backside middle inside leg
region S5 is positioned between the crotch portion region S1 and
the back waistline region S3 in the lengthwise direction L.
[0032] The front waistline side edge portion 4 is bonded with the
back waistline edge portion 6 and the front waistline edge portion
4' is bonded with a back waistline edge portion 6', whereby the
disposable diaper 1 is formed as a pant-type diaper.
[0033] A waist gather 3 is provided in the front waistline region
S2 and the back waistline region S3. The waist gather 3 has an
elongated waist elastic member 3A, such as a synthetic rubber,
which is disposed so as to expand or shrink along a widthwise
direction W of the absorber 40. The waist elastic member 3A is
bonded with an exterior topsheet 70, a foreside exterior backsheet
80F and a backside exterior backsheet 80R by means of an adhesive
(for example, a hot-melt adhesive) in a state in which the member
is expanded along the widthwise direction W of the disposable
diaper 1.
[0034] A leg gather 5 and an absorber crossing gather 7 are formed
at the middle inside leg edge portion 8 of the backside exterior
backsheet 80R. The leg gather 5 is formed so as to be taken along a
wearer's leg portion. The absorber crossing gather 7 is formed so
as to cross the absorber 40 along the widthwise direction W. The
leg gather 5 and the absorbent crossing gather 7 integrally
communicate with each other. The leg gather 5 has a plurality of
leg elastic members 5A, and the absorber crossing gather 7 has a
plurality of crossing elastic members 7A which communicate with the
leg elastic members 5A.
[0035] The disposable diaper 1 is provided with a topsheet 10, an
absorber 40, a side sheet 60, an exterior topsheet 70, a foreside
exterior backsheet 80F, and a backside exterior backsheet 80R. The
topsheet 10, the absorber 40, the side sheet 60, the exterior
topsheet 70, and the foreside exterior backsheets 80F and 80R are
bonded with each other by means of an adhesive or thermal fusion
bonding or the like.
[0036] The topsheet 10 is a sheet forming a skin contact surface
which can come into direct contact with the wearer's skin. The
topsheet 10 is formed of a liquid-permeable sheet such as a
hydrophilic nonwoven cloth or a woven cloth, an aperture plastic
film, or an aperture hydrophilic nonwoven cloth.
[0037] An absorber topside covering sheet 20 is provided between
the topsheet 10 and the absorber 40. The absorber topside covering
sheet 20 is formed of a liquid-permeable sheet such as a
hydrophilic nonwoven cloth or a woven cloth, an aperture plastic
film, an aperture hydrophobic nonwoven cloth, or tissue.
[0038] An absorber backside covering sheet 30 is provided at a
non-skin contact surface side serving as a face opposite to the
topsheet 10 or the absorbent topside covering sheet 20. The
absorber backside covering sheet 30 is formed of a
leakage-preventing sheet such as a liquid-impermeable film (for
example, polyethylene). In FIG. 3, although not shown, the absorber
topside covering sheet 20 is bonded with the absorber backside
covering sheet 30 at a portion at which slits (central slit 45 and
side slits 46L, 46R) are formed.
[0039] The absorber 40 is covered with the absorber topside
covering sheet 20 and the absorber backside covering sheet 30. The
absorber 40 has: a lengthwise direction L which is oriented from
the front waistline region S2 to the back waistline region S3; and
a widthwise direction which is orthogonal to the lengthwise
direction L. Further, the absorber 40 has: an inward direction IN
which is oriented to a wearer wearing the disposable diaper 1 and
an outward direction OUT which is oriented to be opposite to the
inward direction.
[0040] At a side edge portion 50A at which the absorber topside
covering sheet 20 and the absorber backside covering sheet 30
overlap each other at the outside of the widthwise direction W of
the absorber 40, a side elastic member 90 is provided in a state in
which the member expands along the lengthwise direction L. The side
elastic member 90 is continuous from the foreside middle inside leg
region S4 to the backside middle inside leg region S5 through the
crotch portion region S1. The side elastic member is provided
between the absorber backside covering sheet 30 and a side sheet
60. The side elastic member 90 is formed of a synthetic rubber
having elasticity.
[0041] The side sheet 60 is provided so as to integrally cover the
topsheet 10, the absorber topside covering sheet 20, and the
absorber backside covering sheet 30 at both side edges in the
widthwise direction W of the absorber 40. The side sheet 60 is
formed of a sheet such as a liquid-impermeable nonwoven cloth, and
a leakage-preventing wall for preventing side leakage of bodily
waste is comprised of the side sheet 60 and the side elastic member
90.
[0042] The exterior topsheet 70 is formed from the front waistline
region S2 to the back waistline region S3 through the foreside
middle inside leg region S4, the crotch portion region S1, and the
backside middle inside leg region S5. The exterior topsheet 70 is
formed so that its width in the widthwise direction W is greater in
the front waistline region S2 and the back waistline region S3 than
in any other region. The exterior topsheet 70 can be formed of an
air-through nonwoven cloth, a spun bond nonwoven cloth, an SMS
nonwoven cloth, or a water-resistive film or the like.
[0043] The foreside exterior backsheet 80F is provided at a
non-skin contact surface side more than the exterior topsheet 70 in
the front waistline region S2. The backside exterior backsheet 80R
is provided at the non-skin contact surface side more than the
exterior topsheet 70 in the back waistline region S3. One end of
the foreside exterior topsheet 80F in the lengthwise direction Land
one side of the backside exterior backsheet 80R in the lengthwise
direction is folded back to the skin contact surface side, so as to
envelop the end parts in the lengthwise direction L of the exterior
topsheet 70. The foreside exterior backsheet 80F can be formed of
an air-through nonwoven cloth, a spun bond nonwoven cloth, an SMS
nonwoven cloth, or a water-resistive film or the like.
[0044] Materials described in Japanese Patent Application Laid-open
No. 2006-346439, for example, may be employed for constituent
elements constituting the abovementioned disposable diaper 1.
[0045] (2) Structure of an Absorber
[0046] FIG. 5 is a plan view of an absorber 40. As shown in FIG. 5,
the absorber 40 has a central inside leg portion 401, a front
waistline portion 402, a back waistline portion 403, a front middle
inside leg portion 404, and a back middle inside leg portion
405.
[0047] In the embodiment, a width of a narrowed portion of the
front middle inside leg portion 404 which corresponds to the
foreside middle crotch portion S4 is the narrowest. The second
narrowest portion is a width of the central inside leg portion 401
positioned in the crotch portion region S1 (see FIG. 1).
[0048] It should be appreciated that the absorber is not limited to
the depicted shape, the absorber may take other forms, as will be
readily appreciated by those skilled in the art.
[0049] In the embodiment, the absorber 40 is employed as the one in
which a water absorbent polymer is incorporated into a cotton-like
pulp of 200 g/m.sup.2. In addition, a central slit 45 and a side
slit 46L, side slit 46R are formed at the absorber 40 as described
above.
[0050] The central slit 45 is formed at the absorber 40 along the
lengthwise direction L, namely so that the absorber 40 can be
curved to a wearer so as to be convex in the inward direction IN.
In the embodiment, the central slit 45 comprises a central curve
forming portion. The side slit 46L, the side slit 46R are formed at
the absorber 40 along the lengthwise direction L, namely so that
the absorber 40 can be curved to be convex in the outer direction
OUT either side of the central slit 45. In the embodiment, the side
slit 46L, the side slit 46R comprise side curve forming
portions.
[0051] A width of the central slit 45 is preferably about 10 mm,
and a length thereof is preferably about 200 mm. The width of the
side slit 46L, side slit 46R is preferably about 10 mm and a length
thereof is preferably about 120 mm. In addition, the thickness of
the absorber 40 is preferably about 2.0 mm.
[0052] FIG. 6 is a partially enlarged plan view of the absorber 40.
As shown in FIG. 6, the absorber 40 has a central portion CT formed
at a central part of the absorber 40 in the widthwise direction W.
In addition, the absorber 40 has a pair of side edge portions
S.sub.L, S.sub.R formed at a side edge 40e of the absorber 40 in
the widthwise direction W. Further, this absorber has a pair of
middle portions M.sub.L, M.sub.R positioned between the central
portion and the side edge portions. The central portion CT, the
middle portion M.sub.L, the middle portion M.sub.R, the side edge
portion S.sub.L, and the side edge portion S.sub.R are formed at
least in a crotch portion region S1 (central inside leg portion
401).
[0053] The central portion CT includes a sub-central portion 47L
and a sub-central portion 47R which are regions from the boundaries
associated with the middle portion M.sub.L and the middle portion
M.sub.R respectively to the central slit 45 in the widthwise
direction W.
[0054] The middle portions M.sub.L , M.sub.R each include an inside
middle portion 48L, 48R, which is a region from the respective side
slit 46L, 46R to a boundary associated with the central portion CT
in the widthwise direction. In addition, each middle portion
M.sub.L, M.sub.R includes an outside middle portion 49L, 49R which
is a region from a respective one of the side slits 46L, 46R to a
boundary associated with a respective one of the side edge portions
S.sub.L, S.sub.R in the widthwise direction W.
[0055] The central portion CT is deformed so that the absorber 40
is curved at a portion of the central slit CT to be convex toward a
wearer. The middle portions M.sub.L , M.sub.R including the side
slits 46L, 46R are deformed at a side opposite to the central
portion CT, namely so as to be convex at the non-skin contact
surface side. Specifically, the central portion CT is convex toward
the wearer in a state in which it is sandwiched between the
wearer's legs, whereas the side edge portions S.sub.L, S.sub.R rise
to the wearer's side by shrinkage of the side elastic member 90.
The middle portions M.sub.L, M.sub.R are folded at a portion of the
respective side slits 46L, 46R, and are convex at a side opposite
to the central portion CT.
[0056] The middle portions M.sub.L, M.sub.R are formed from
positions which correspond to half of a distance D1 between a
center CT1 of the central slit 45 and a center CT2 of the
respective side slit 46L, 46R to a position which corresponds to
half of a distance D2 between the respective side slit 46L, 46R and
a respective side edge 40e of the absorber 40. In the embodiment,
the distance D1 is preferably set to about 40 mm and the distance
D2 is preferably set to about 35 mm. In addition, in the widthwise
direction W, the width of the sub-central portions 47L, 47R is
substantially identical to that of the side edge portions S.sub.L,
S.sub.R.
[0057] An average total weight of a water absorbent polymer at the
central portion CT and the side edge portion S.sub.L, the side edge
portion S.sub.R is preferably 90 g/m.sup.2. On the other hand, an
average total weight of a water absorbent polymer at the middle
portion M.sub.L, the middle portion M.sub.R is preferably 240
g/m.sup.2. That is, the average total weight of the water absorbent
polymer at the central portion CT and the side edge portion
S.sub.L, the side edge portion S.sub.R is smaller than that of the
water absorbent polymer at the middle portion M.sub.L, the middle
portion M.sub.R.
[0058] The average total weight of the water absorbent polymer is a
mass of the water absorbent polymer incorporated per a unit area of
the portion, and even if a total weight is different in the portion
(for example, middle portion M.sub.L), such total weight is defined
as a value obtained by averaging the mass of the water absorbent
polymer incorporated in an area of the portion by a unit area. The
central slit 45 and the side slits 46L, 46R are not incorporated in
computation of an average total weight, since neither a pulp nor a
water absorbent polymer exists.
[0059] A high total weight portion SP at which the average total
weight of the water absorbent polymer at the middle portions
M.sub.L, M.sub.R is 240 g/m.sup.2 is formed around the side slits
46L, 46R. For example, a water absorbent polymer having properties
of water absorption magnification of 64 g/g, water retention
magnification of 40 g/g, and absorption velocity (Vortex approach)
of 29 seconds can be employed.
[0060] A testing method using the Vortex approach is generally as
follows. First, sodium chloride of 27.0 g (reagent: grade 1) and
ion exchange water are added to hydrochloride water solution
(reagent: grade 1) to make a solution of 3,000.0 g and then the
resultant solution is stirred until it is dissolved. In addition, a
testing liquid of 1 liter of the solution above is put into a
beaker; a temperature of the testing liquid is adjusted to 25
degrees Centigrade+-1 degree Centigrade; and a testing liquid of 50
g is transferred to a beaker of 100 ml. The beaker is placed on a
magnetic stirrer (MITAMURA RIKEN KOGYO INC. MAGMIX STIRRER), and is
stirred at 600 rotations per minute. The number of rotations is
adjusted to 600+-30 rotations per minute.
[0061] Next, a water absorbent polymer (SAP) of 2.00 g is entered
into the beaker, and time is measured until a liquid surface
becomes smooth. A judgment as to whether or not the liquid surface
becomes smooth is based on the fact that an inclination of whirl of
the liquid that is severely rotating is close to a plane, and is
made by observing whether illumination reflected on the liquid
surface of the whirl goes up or out.
[0062] It is preferable that the average total weight of the water
absorbent polymer at the central portion CT and side edge portions
S.sub.L, S.sub.R is 0 g/m.sup.2 or more and 300 g/m.sup.2 or less,
and it is more preferable that the weight is 0 g/m.sup.2 or more
and 90 g/m.sup.2 or less. In addition, it is preferable that the
average total weight of the water absorbent polymer at the middle
portion M.sub.L (middle portion M.sub.R) is 100 g/m.sup.2 or more
and 600 g/m.sup.2 or less and it is more preferable that the weight
is 100 g/m.sup.2 or more and 400 g/m.sup.2 or less. However, the
average total weight of the water absorbent polymer at the central
portion CT and the side edge portions S.sub.L, S.sub.R is less than
that of the water absorbent polymer at the middle portions M.sub.L,
M.sub.R.
[0063] In addition, it is preferable that the average total weight
of the water absorbent polymer at the sub-central portions 47L, 47R
is less than that of the water absorbent polymer at the inside
middle portions 48L, 48R. Further, it is preferable that the
average total weight of the water absorbent polymer at the side
edge portions S.sub.L, S.sub.R is less than that of the water
absorbent polymer at the outside middle portions 49L, 49R.
[0064] (3) Shape Change of an Absorber
[0065] FIG. 7(a) is a sectional view (which is taken along the line
A-A of FIG. 2) schematically showing a state in which the absorber
40 has not absorbed bodily waste, and FIG. 7(b) is a sectional view
(which is taken along the line A-A of FIG. 2) schematically showing
a wearing state of the disposable diaper 1 in a state in which the
absorber 40 absorbs bodily waste.
[0066] As shown in FIG. 7(a), when the disposable diaper 1 is worn,
the absorber 40 is curved with respect to the central slit 45 and
the side slits 46L, 46R, and the cross-sectional shape that is
taken along the widthwise direction W of the disposable diaper 1 is
deformed at the W-letter shape. As a result, a sub-central portion
47L, a sub-central portion 47R, a side edge portion S.sub.L, and a
side edge portion S.sub.R are positioned at an upper area 40U which
is proximal to a wearer's body above an imaginary line M obtained
by dividing a height 40L of the deformed absorber 40 into two
sections. On the other hand, in an elevation direction T, inside
middle portions 48L, 40R and outside middle portions 40L, 40R are
positioned in a lower area 40D which is distant from the wearer's
body and below the imaginary line M.
[0067] FIG. 7(b) shows a wearing state of the disposable diaper 1
in a state in which the absorber 40 absorbs bodily waste. As shown
in FIG. 7(b), when the absorber 40 absorbs a predetermined amount
of liquid such as urine, the inside middle portions 48L, 48R and
outside middle portions 49L, 49R of which average total weight of
the water absorbent polymer is large swell more than the
sub-central portion 47L, sub-central portion 47R and the side edge
portions S.sub.L, S.sub.R of which average total weight of the
water absorbent polymer is small. Thus, in a case where the
absorber 40 absorbs a pre-determined amount of liquid, a total
thickness of the absorber 40 in the central portion CT and side
edge portions S.sub.L, S.sub.R becomes smaller than that of the
absorber 40 in the inside middle portions 48L, 48R and the outside
middle portion 49L, 49R.
[0068] FIG. 8 is a sectional view schematically showing a wearing
state of the disposable diaper 1 in a state in which the absorber
absorbs bodily waste, specifically a case in which a wearer closes
his or her legs. The imaginary line in the figure indicates the
wearer's crotch portion and both leg portions.
[0069] As shown in FIG. 8, if the wearer closes his or her legs in
a state in which the absorber 40 absorbs bodily waste, the
cross-sectional shape of the disposable diaper 1 varies from the
state shown in FIG. 7(b) to the state shown in FIG. 8. At this
time, the thickness of the absorber 40 in the upper region 40U (a
total thickness of W21 to W24 in the figure), in which an expansion
rate after absorption of liquid (about 500 cc) is lower, is about
18 mm. Specifically, the thickness before liquid absorption is
about 2.0 mm in a region in which the average total weight of the
water absorbent polymer is 90 g/m.sup.2, whereas the thickness
after liquid absorption is about 4.5 mm. Namely, the thicknesses
W21 to W24 of the sub-central portion 47L, sub-central portion 47R
and the side edge portions S.sub.R, S.sub.L are about 4.5 mm,
respectively. The thicknesses W21 to W24 are a thickness of the
absorber 40 at a position which is lowered by a distance of 1/3 of
the upper region 40U from an upper end of the upper region 40U in
the elevation direction T.
[0070] On the other hand, the thickness of the absorber 40 in the
lower region 40D (a total thickness of W11 to W14 in the figure) is
larger than that of the absorber 40 in the upper region 40U. Thus,
the cross-sectional shape that is taken along the widthwise
direction W of the absorber 40 (disposable diaper 1) is formed in a
tapered shape toward the wearer's crotch portion. The thicknesses
W11 to W14 are a thickness of the absorber 40 at a position rising
by a distance of 1/3 of the lower region 40D from a lower end of
the lower region 40D in the elevation direction T.
[0071] In a case where the absorber 40 absorbs a predetermined
amount of liquid (about 500 cc), it is preferable that the
thickness of a high total weight portion SP (the thickness of the
disposable diaper 1 at the positions of W11 to W14 of FIG. 8) in a
state in which the absorber 40 is curved is 20 mm or more and 120
mm or less, it is more preferable that the thickness is 20 mm or
more and 80 mm or less, and it is further preferable that the
thickness is 20 mm or more and 40 mm or less. In addition, it is
preferable that the thickness of a portion other than the high
total weight portion SP (the thickness of the disposable diaper 1
at the positions of W21 to S24 of FIG. 8) in a state in which the
absorber 40 is curved is low, preferably 4 mm or more and 20 mm or
less. In a case where the thicknesses W11 to W14 of the lower
region 40D are increased, the higher the central portion CT taken
along the elevation direction T is, namely, the wider the central
portion CT prior to deforming the absorber 40 is, the more easily
the central portion CT enters the wearer's crotch portion.
[0072] The disposable diaper 1 described hereinbefore is provided
with: the central slit 45 formed at the absorber 40 so that the
absorber 40 can be curved to be convex toward a wearer; and a pair
of side slits 46L, 46R which are formed at the absorber 40 so that
the absorber 40 can be curved to be convex so as to be oriented to
a side opposite to the central slit 45. Thus, at the time of
wearing the disposable diaper 1, the central portion CT that is
formed to be convex toward the wearer's excretion portion easily
comes into intimate contact with the excretion portion. In
addition, the middle portion M.sub.L and the middle portion M.sub.R
each form a concave portion, so that bodily waste easily enters the
concave portion, and direct contact between the wearer's skin and
bodily waste can be restrained.
[0073] Further, the average total weight (90 g/m.sup.2) of the
water absorbent polymer at the central portion CT and the side edge
portions S.sub.L, S.sub.R is less than the average total weight
(240 g/m.sup.2) of the water absorbent polymer at the middle
portions M.sub.L, M.sub.R. Specifically, the average total weight
of the water absorbent polymer at the sub-central portions 47L, 47R
is less than that of the water absorbent polymer at the inside
middle portions 48L, 48R; and the average total weight of the water
absorbent polymer at the side edge portions S.sub.L, S.sub.R is
less than that of the water absorbent polymer at the outside middle
portions 49L, 49R.
[0074] Therefore, after the absorber 40 absorbs a predetermined
amount of liquid, the thickness of the central portion CT and the
side edge portions S.sub.L, S.sub.R, which have a low average total
weight of the water absorbent polymer, is (smaller than that of the
middle portion M.sub.L and the middle portion M.sub.R in which the
average total weight is large.
[0075] Thus, the central portion CT, which is proximal to the
wearer's crotch portion, and the side edge portions S.sub.L,
S.sub.R are restrained in thickness after liquid absorption, the
wearer hardly has an uncomfortable feeling, and it is ensured that
the absorber comes into intimate contact with the excretion
portion. In addition, at the middle portion M.sub.L and the middle
portion M.sub.R, each of which is distant from the wearer's crotch
portion, the average total weight of the water absorbent polymer is
large, so that absorptive power can be improved without the wearer
having an uncomfortable feeling. In particular, after bodily waste
such as urine has been absorbed a plurality of times, such a shape
can be maintained to prevent the wearer from having an
uncomfortable feeling or leakage of bodily waste.
[0076] In the embodiment, the middle portions M.sub.L, M.sub.R are
formed, in the widthwise direction W, from a position which
corresponds to half of the distance D1 between a center CT1 of the
central slit 45 and a center CT2 of the side slit 46L (or the side
slit 46R) to a position which corresponds to half of the distance
D2 between the side slit 46L (or the side slit 46R) and the side
edge 40e of the absorber 40. In addition, the width of the
sub-central portions 47L, 47R is substantially identical to that of
the side edge portions S.sub.L, S.sub.R. Thus, as shown in FIG.
7(a) and FIG. 7(b), among the upper region 40U and the lower region
40D that are obtained by dividing the curved absorber 40 into two
sections, the central portion CT and the side edge portions
S.sub.L, S.sub.R can be disposed, in the elevation direction T, in
the upper region 40U that is proximal to the wearer's crotch
portion; and the middle portions M.sub.L, M.sub.R can be disposed
in the lower region 40D that is distant from the wearer's inside
leg portion. Namely, the thickness of the absorber 40 in the upper
region 40U is restrained, and an uncomfortable feeling of the
wearer or leakage of bodily waste can be reliably prevented.
[0077] In the embodiment, the absorber topside covering sheet 20 is
bonded with the absorber backside covering sheet 30 at a portion at
which slits (central slit 45 and side slits 46L, 46R) are formed.
Thus, deformation of the absorber 40 causing a slit portion to
close or twisting of the absorber 40 from a slit portion can be
restrained. In addition, even in a case where the absorber 40
absorbs liquid and swells, closing of a slit portion can be
restrained. Therefore, a slit portion can easily function as a
curve forming portion reliably.
[0078] (4) First Modification
[0079] FIG. 9 is a partially enlarged plan view of an absorber 40X
according to a modification of the embodiment. As shown in FIG. 9,
in the absorber 40X, in a lengthwise direction L, an average total
weight of a water absorbent polymer in a region positioned at an
outside of the central portion CT is more than that of a water
absorbent polymer at the central portion CT.
[0080] Specifically, an average total weight of a water absorbent
polymer at the foreside middle inside leg region S4, which is a
portion close to the front waistline region S2 and adjacent to a
central inside leg portion 401 (crotch portion region S1), and at
the backside middle inside leg region S5, which is a portion close
to a back waistline region S3 and adjacent to the crotch portion
region S1, is more than that of a water absorbent polymer at the
central portion CT positioned in the crotch portion region S1. For
example, a total weight of the portions can be set to 240 g/m.sup.2
like the middle portions M.sub.L, M.sub.R.
[0081] Namely, in the absorber 40X, the longitudinal and transverse
extending peripheries of a sub-central portion 47L and a
sub-central portion 47R of the portion of the central portion CT
extending the length of crotch region S1 are surrounded by an area
in which an average total weight of a water absorbent polymer is
large. An outside region, in the lengthwise direction L, of the
central portion CT, that is the region that lies outside the crotch
portion S1, is hardly deformed if the absorber absorbs liquid and
swells greatly, and thus, W-letter shaped deformation at the
central inside leg portion 401 of the absorber 40X does not have an
influence on the region, and the region is easily maintained to be
planar. In addition, an outside region, in the lengthwise direction
L, beyond the crotch portion region S1 is not sandwiched by a
wearer's crotch portion, so that an average total weight of the
water absorbent polymer of this portion is increased, whereby
absorptive power can be improved without increasing an
uncomfortable feeling at the crotch portion.
[0082] (5) Second Modification
[0083] FIG. 10 and FIG. 11 are sectional views (which is taken
along the line A-A of FIG. 2) of a disposable diaper 1 including an
absorber 40Y and an absorber 40Y' according to the modification of
the embodiment. As shown in FIG. 10 and FIG. 11, a thickness of an
absorber at any of at least a central portion CT and a side edge
portion S.sub.L and a side edge portion S.sub.R is smaller than
that of an absorber at a middle portion M.sub.L and a middle
portion M.sub.R. The reduced thickness portions may extend for the
length of the crotch portion region S1 only.
[0084] According to the absorbent 40Y and the absorbent 40Y', the
absorber 40Y (absorber 40Y') may adopt the state shown in FIG. 8
before the absorber absorbs liquid. Thus, absorptive power of the
disposable diaper 1 is improved, whereas a feeling of wearing
before liquid absorption can also be improved.
[0085] The thickness of the side edge portion S.sub.L and the side
edge portion S.sub.R may be increased like the middle portion
M.sub.L and the middle portion M.sub.R, like the absorber 40Y, as
shown in FIG. 10, so that the side edge portions have the same
thickness as the middle portions, or alternatively, may be
decreased like the central portion CT as in the absorber 40Y', as
shown in FIG. 11, where the thickness of the side edge portions is
equal to the thickness of the central portion, wherein in both
cases the thickness of the central portion is less than the
thickness of the middle portions.
Second Embodiment
[0086] FIG. 12 is a perspective view of a simple absorber 40Z
according to a second embodiment. FIG. 13 is a sectional view
(which is taken along the line A-A of FIG. 2) of a disposable
diaper 1 including an absorber 40Z. As shown in FIG. 12 and FIG.
13, an absorber 40Z according to the embodiment is a two-layer
structure.
[0087] Specifically, the absorber 40Z has a first layer 41 and a
second layer 42 which are superimposed on one another. The first
layer 41 is positioned at a skin contact surface side with a
wearer, and the second layer 42 is positioned at a non-skin contact
surface side of the wearer. Side slits 41L, 41R extending along a
lengthwise direction L are formed at the first layer 41. The side
slits 41L, 41R are formed at a crotch portion region S1 (central
inside leg portion 401) like side slits 46L, 46R.
[0088] In the second layer, a central aperture 42C extending along
the lengthwise direction L is formed and side slits 42L, 42R are
also formed. The central aperture 42C and the side slits 42F, 42R
are formed at a crotch portion region S1 (central inside leg
portion 401) like the central slit 45 or the like. A width of the
central aperture 42C is preferably about 40 mm, and the side slits
41L, 41R and the side slits 42L, 42R are preferably about 10 mm
wide.
[0089] In the case of the absorber 40Z, as shown in FIG. 13, the
central portion CT is formed of only the first layer 41, the side
edge portions S.sub.L, S.sub.R are formed only of the first layer
41, and a middle portion M.sub.L and a middle portion M.sub.R are
formed of the first layer 41 and the second layer 42. In addition,
an average total weight of a water absorbent polymer in the first
layer 41 is preferably 90 g/m.sup.2. An average total weight of a
water absorbent polymer in the second layer 42 is preferably 150
g/m.sup.2. Thus, as in the first embodiment, an average total
weight of a water absorbent polymer at the central portion CT and
the side edge portion S.sub.L, the side edge portion S.sub.R is
preferably 90 g/m.sup.2, and an average total weight of a water
absorbent polymer at the middle portion M.sub.L, the middle portion
M.sub.R is preferably 240 g/m.sup.2.
[0090] In addition, in the disposable diaper 1, including the
absorber according to the embodiment, a central elastic member 95
(central curve forming portion) is provided between an absorber
backside covering sheet 30 and an elastic member covering sheet 96.
The central elastic member 95 is provided as a plurality of elastic
strands along the lengthwise direction L to thereby deform the
absorber 40Z so that the central portion CT becomes convex toward a
wearer. Thus, in the disposable diaper 1 according to the
embodiment, unlike the central slit 45 (see FIG. 3), a slit
penetrating in the elevation direction T is not formed. It should
be noted that the central elastic member is not limited to a
plurality of elastic strands but may take other forms as will be
readily appreciated by those skilled in the art.
[0091] With the second layer 42 being positioned at a skin contact
surface with a wearer, the first layer may be positioned at the
wearer's non-skin contact surface side. According to the disposable
diaper 1 according to the embodiment, since there is employed the
absorber 40Z in which the first layer 41 and the second layer 42
are superimposed on each other, an absorber of which thickness is
different depending on a portion can be easily manufactured in
comparison with a case in which an absorber of a one-layer
structure is employed.
Other Embodiments
[0092] As described above, while the contents of the present
invention have been disclosed through the embodiments of the
present invention, it should not be understood that the statements
and drawings forming part of the disclosure limit the present
invention. From this disclosure, a variety of alternative
embodiments, examples, and operational techniques would be
self-evident to one skilled in the art.
[0093] For example, while, the absorber of the first and second
embodiments has been described in combination with a pant-type
disposable diaper 1, the absorber of the present invention may be
applied to numerous other absorbent wearing articles, including but
not limited to an open-type disposable diaper or a sanitary
napkin.
[0094] While, in the first embodiment described above, the middle
portions M.sub.L, M.sub.R were formed from positions corresponding
to half of the distance D1 between the center CT1 of the central
slit 45 and the center CT2 of the respective side slit 46L, 46R to
a position which corresponds to half of the distance D2 between the
side slit 46L, 46R and the respective side edge 40e of the absorber
40, the middle portions M.sub.L, M.sub.R may not always be formed
at such a range. For example, a total width of the middle portions
M.sub.L, M.sub.R may be smaller than the width of the central
portion CT.
[0095] While, in the first embodiment described above, the average
total weight (90 g/m.sup.2) of the water absorbent polymer at the
central portion CT and the side edge portions S.sub.L, S.sub.R was
smaller than the average total weight (240 g/m.sup.2) of the water
absorbent polymer at the middle portions M.sub.L, M.sub.R, for
example, the total weight of the water absorbent polymer at the
side edge portions S.sub.L, S.sub.R may be identical to that of the
water absorbent polymer at the middle portions M.sub.L, M.sub.R. In
addition, the total weight of the side edge portions S.sub.L and
S.sub.R, the middle portions M.sub.L and M.sub.R, the sub-central
portions 47L and 47R may not always be identical to each other. For
example, if the average total weight of the side edge portion
S.sub.L is 90 g/m.sup.2 and the average total weight of the side
edge portion S.sub.R is 100 g/m.sup.2, the average total weight of
the entire side edge portion S.sub.L, the side edge portion S.sub.R
is 95 g/m.sup.2.
[0096] While, in the first embodiment described above, the average
total weight (90 g/m.sup.2) of the water absorbent polymer at the
central portion CT and the side edge portions S.sub.L, S.sub.R was
smaller than the average total weight (240 g/m.sup.2) of the water
absorbent polymer at the middle portion M.sub.L, with the average
total weight of each portion being identical, a water absorption
magnification of the water absorbent polymer at the central portion
CT and the side edge portions S.sub.L, S.sub.R may be smaller than
that of the water absorbent polymer at the middle portions M.sub.L,
M.sub.R. For example, while the water absorption magnification of
the water absorbent polymer at the central portion CT and the side
edge portions S.sub.L, S.sub.R is on the order of 40 g/g, the water
absorption magnification of the water absorbent polymer at the
middle portions M.sub.L, t M.sub.R may be on the order of 60 g/g.
By disposition of such a water absorbent polymer as well, an
advantageous effect similar to that of the above-described absorber
can be attained.
[0097] While, in the first and second embodiments described above,
a central curve forming portion was formed by employing slits or
elastic members, the central curve forming portion may be formed by
other means, such as but not limited to reducing the thickness of
an absorber or applying emboss processing to the absorber.
[0098] Of course, the present invention includes a variety of
embodiments which are not described herein. Therefore, a technical
scope of the present invention is defined merely by specific
matters of the invention according to a scope of claims which is
reasonable from the above description.
[0099] The first aspect of the present invention described above
may be arranged in at least the following items:
[0100] An absorber having a lengthwise direction; a widthwise
direction which is orthogonal to the lengthwise direction; an
inward direction which is oriented to a wearer; and an outer
direction which is oriented to a side opposite to the inward
direction, the absorber including a water absorbent polymer,
wherein: the absorber has, in a crotch portion region applied to a
crotch portion of the wearer, a central portion which is formed at
a central part of the absorber in the widthwise direction, a pair
of side edge portions including a side edge of the absorber in the
widthwise direction, and a pair of middle portions which are
positioned between the central portion and the side edge portions;
at the central portion, a central curve forming portion is formed
along the lengthwise direction so that the absorber can be curved
to be convex in the inward direction; at each of the middle
portions, a side curve forming portion is formed along the
lengthwise direction so that the absorber can be curved to be
convex in the outward direction; and an average total weight of the
water absorbent polymer at the central portion is smaller than an
average total weight of the water absorbent polymer at the middle
portions.
[0101] A disposable wearing article comprising an absorber
according to the preceding item or any of the foregoing items.
[0102] Additionally, one or more of the following embodiments are
provided in accordance with further aspects:
[0103] Preferably, the average total weight of the water absorbent
polymer at the side edge portions is smaller than the average total
weight of the water absorbent polymer at the middle portions.
[0104] The average total weight of the water absorbent polymer at
the side edge portions may be the same as the average total weight
of the water absorbent polymer at the middle portions.
[0105] The average total weight of the water absorbent polymer at
the side edge portions may be the same as the average total weight
of the water absorbent polymer at the central portion.
[0106] Preferably, the middle portions each include an inside
middle portion which is a region from the side curve forming
portion to a boundary associated with the central portion in the
widthwise direction; the central portion includes a sub-central
portion from a boundary associated with a respective one of the
middle portions to the central curve forming portion in the
widthwise direction; and an average total weight of the water
absorbent polymer at the sub-central portion is less than an
average total weight of the water absorbent polymer at the inside
middle portion.
[0107] Preferably, the middle portions each include an outside
middle portion which is a region from the side curve forming
portion to a boundary associated with a respective one of the side
edge portions in the widthwise direction; and an average total
weight of the water absorbent polymer at the side edge portion is
smaller than an average total weight of the water absorbent polymer
at the outside middle portion.
[0108] Preferably, one or both of the middle portions is formed, in
the widthwise direction, from a position which corresponds to half
of a distance between a center of the central curve forming portion
and a center of the side curve forming portions, to a position
which corresponds to half of a distance between the center of the
side curve forming portion and a side edge of the absorber.
[0109] Preferably, in the widthwise direction, a width of the
central portion is identical to a width of one or both of the side
edge portions.
[0110] Preferably, in the lengthwise direction, an average total
weight of the water absorbent polymer in a region positioned
outside of the central portion is larger than an average total
weight of the water absorbent polymer at the central portion.
[0111] The central portion preferably extends, in the lengthwise
direction, across the length of the crotch portion region only,
i.e. it is bounded in the lengthwise direction by the inner
boundaries of the backside middle inside leg region and the
foreside middle inside leg region.
[0112] Preferably, a thickness of the absorber in the central
portion only, in the side edge portion only, or in both the central
portion and the side edge portion is smaller than a thickness of
the absorber at the middle portion.
[0113] The absorber may have a first layer and a second layer which
are superimposed on one another; the central portion and the side
edge portion being formed of only the second layer; and the middle
portion being formed of the first layer and the second layer.
Alternatively, only the central portion is formed of only the first
layer; and the middle portion and the side edge portion are formed
of the first layer and the second layer.
[0114] Preferably, the average total weight of the water absorbent
polymer in the first layer is smaller than the average total weight
of the water absorbent polymer in the second layer.
[0115] Preferably, the second layer is positioned at a skin contact
surface side with the wearer; and the first layer is positioned at
a non-skin contact surface side of the wearer.
[0116] Preferably, the central curve forming portion is formed of a
central slit which is formed at the absorber along the lengthwise
direction, or is formed of a central elastic member which is
disposed along the lengthwise direction.
[0117] Preferably, the side curve forming portion is formed of a
side slit which is formed at the absorber along the lengthwise
direction.
[0118] The absorber may be provided with a topside covering sheet
and a backside covering sheet, which is provided on a non-skin
contact surface side of the absorber, wherein the topside covering
sheet is bonded to the backside covering sheet at a portion at
which one or more slits comprising the central curve forming
portion and/or the side curve forming portions are formed.
[0119] A thickness of the absorber at the central portion and at
each of the side edge portions may be smaller than that of the
absorber at the middle portions. Alternatively, the absorber may be
thinner at the central portion only. In this case, the thicknesses
of the side edge portions and the middle portions may be equal.
[0120] A water absorption magnification of the water absorbent
polymer at the central portion and the side edge portions may be
smaller than that of the water absorbent polymer at the middle
portions.
[0121] According to the embodiments in the above paragraphs, the
features of which may be taken in isolation or in combination with
one another, the advantageous effect(s) of the present invention
is/are better ensured. Further advantageous effects of the
respective embodiments may be obtained as discussed in the
respective related descriptions.
[0122] Note that this application claims the benefit of Japanese
Application No. 2010-043596 the entire disclosure of which is
incorporated by reference herein.
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